Not to be a downer, but no, the interview is not a small formal final step 😕
In my experience, there was no way I could have known that my previous troubles at the border would have delayed processing my visa. They will ask you questions about any possible issues you’ve had before because they’ve got all of your history in front of them during the interview. They knew about my student visas and all my border crossings and asked me questions to confirm what happened.
They might still approve the visa, but in my case, they put me administrative processing because they needed to look more into it.
Don’t worry too much about it now. Just be honest and roll with the punches. Nothing you can do 🤷🏼♀️